source: xtideuniversalbios/trunk/Assembly_Library/Src/Util/Math.asm@ 572

; Project name  :   Assembly Library
; Description   :   Functions for register operations.

;
; XTIDE Universal BIOS and Associated Tools
; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
;


; Section containing code
SECTION .text

;--------------------------------------------------------------------
; Math_DivQWatSSBPbyCX
;   Parameters:
;       [SS:BP]:    64-bit unsigned divident
;       CX:         16-bit unsigned divisor
;   Returns:
;       [SS:BP]:    64-bit unsigned quotient
;       DX:         16-bit unsigned remainder
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS OR EXCLUDE_FROM_XTIDECFG
ALIGN JUMP_ALIGN
Math_DivQWatSSBPbyCX:
    xor     dx, dx
    mov     ax, [bp+6]      ; Load highest divident WORD to DX:AX
    div     cx
    mov     [bp+6], ax      ; Store quotient

    mov     ax, [bp+4]
    div     cx
    mov     [bp+4], ax

    mov     ax, [bp+2]
    div     cx
    mov     [bp+2], ax

    mov     ax, [bp]
    div     cx
    mov     [bp], ax
    ret
%endif


;--------------------------------------------------------------------
; Math_DivDXAXbyCX
;   Parameters:
;       DX:AX:  32-bit unsigned divident
;       CX:     16-bit unsigned divisor
;   Returns:
;       DX:AX:  32-bit unsigned quotient
;       BX:     16-bit unsigned remainder
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
%ifndef EXCLUDE_FROM_XTIDECFG
ALIGN JUMP_ALIGN
Math_DivDXAXbyCX:
    xor     bx, bx
    xchg    bx, ax
    xchg    dx, ax
    div     cx
    xchg    ax, bx
    div     cx
    xchg    dx, bx
    ret
%endif